The origin of visible photoluminescence from silicon oxide thin films prepared by dual-plasma chemical vapor deposition

Abstract

In order to understand the radiative recombination mechanisms in silicon oxides, photoluminescence properties (PL) of H-rich amorphous silicon oxide thin films grown in a dual-plasma chemical vapor deposition reactor have been related to a number of stoichiometry and structure characterizations (x-ray photoelectron spectroscopy, vibrational spectroscopy, and gas evolution studies). The visible photoluminescence at room temperature from a-SiOx:H matrixes with different compositions, including different bonding environments for H atoms, has been studied in the as-deposited and annealed states up to 900 °C. Three commonly reported PL bands centered around 1.7, 2.1, and 2.9 eV have been detected from the same type of a-SiOx:H material, only by varying the oxygen content (x = 1.35, 1.65, and 2). Temperature quenching experiments are crucial to distinguish the 1.7 eV band, fully consistent with bandtail-to-bandtail recombination, from the radiative defect luminescence mechanisms attributed either to defects related to Si–OH groups (2.9 eV) or to oxygen-vacancy defects (2.1 eV). In the latter case, a red-shift of the PL peak energy as a function of annealing temperature is probably attributed to some matrix-induced strain effect.

Optical and structural properties of Si nanocrystals produced by Si hot implantation

“…Although the exact mechanism for light emission remains controversial, nowadays it is well established that basically it relies either on NC size effects [7][8][9] or on radiative processes at the Si NCs/matrix interface. [9][10][11][12] Several techniques have been used to produce Si NCs embedded in a SiO 2 matrix, among them chemical vapor deposition ͑CVD͒, molecular beam epitaxy ͑MBE͒, laser ablation, and in particular the ion implantation technique. This last one has been used quite frequently because it has several advantages.…”

Photoluminescence from Pressure — Annealed Nanostructured Silicon Dioxide and Nitride Films

“…PL at about 2.9 eV (430 nm) was detected for silicon oxide thin films prepared by dual plasma CVD [10]. This may be related to a defect associated with the OH groups.…”

Structure and properties of white Si–O–C(–H) ceramics derived from polycarbosilane by thermal oxidation curing and H₂ decarbonization process

“…These other PL components are possibly assigned to defects introduced in SiOC(H) ceramics. 13) Adoption of short wavelength for excitation (300 nm) in this case may strengthen the intensity of sub-peaks at 350 and 450 nm. In the case of SiOC(H) ceramics derived from silicone resin at 800°C, however, main peak position did not shift by using short wavelength for excitation, although PL spectrum began to show shoulder at short wavelength region.…”